Re: [Xen-devel] Request for help, implementing a new network scheduler

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Tue, Feb 03, 2015 at 01:42:09AM +0100, Ronald PIna wrote:
> Hi
> 

Hello

> I am working for the msc thesis to improve the performance on network for
> guest domains that uses real-time services like voip or video streaming
> servers , i have an idea to implement a network scheduler on network
> backend, the schedulers may be weighted fair queuing or weighted round
> robin,  the idea is to schedule first the packet coming from real-time guest
> services, one of those schedulers could make the job and can prioritize the
> network traffic.
> 
> As far as i have studied from previous works explain that the outgoing
> network traffic in xen is scheduled in round robin manner inside the
> function net_tx_action(). Later on the last version of xen this function has
> changed xenvif_tx_action() and have changed his primarily structure. My

I take it you're looking at Linux source code because xenvif_tx_action
is in Linux. Keep in mind that there is indeed other implementations of
netback, say, the FreeBSD netback and the ClickOS guys own
implementation.

I think net_tx_action to xenvif_tx_action is mostly a name change. But
the internal model of netback did change drastically in the last few
years. If you want to work on netback you'd better work on upstream
Linux netback.

> primarily goal is to modify the round robin to more advanced scheduler
> which introduce priorities. The clear question is that where is located the
> function which schedule in round robin and if possible are there any concern
> about using another network scheduling method in netback ?
> 

Upstream netback has a 1:1 model, which means every frontend stream has
one serving routine in the backend. And we rely on Linux's scheduler to
make sensible decision.

So if you want to change scheduler you're heading into instrumenting
Linux's scheduler to meet your need. YMMW.

Wei.

> Thanks in advance
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel